The conspicuous absence of the Twin Towers – involving, as it does, the inherent conflicts between Christianity, Islam and Judaism – is, I think, one of the most powerful expressions of religious fanaticism in the late 20th and early 21st centuries.

Perhaps I was too dumb, or just too interested in cricket or in girls, to ask myself any questions about religion. If I had not been, I might have, inevitably, asked myself questions that have troubled skeptics and unbelievers for as long as men and women have been skeptical or have lacked belief. "Is there really no God? And if there really is no supernatural dimension to the universe, why have so many people throughout history and in so many different cultures thought there was?"

Episode one: "Shadows of Doubt"

Paradoxically, some of the sources of disbelief are to be found amongst the arguments of believers. … Theologians often formulated the most dangerously skeptical arguments in their efforts to test the impregnability of their own faith, and in doing so, they unknowingly furnished atheists with ready-made weapons.

Episode one: "Shadows of Doubt"

[In casual conversation] The reason why I feel relatively indifferent to [the Anglican Church of England] is it's lost its power, and it's so desperately keen to solicit support that they're willing to throw God out of the window in order to retain it. God for the many of the Anglicans is nothing more than a sort of awkward geriatric relative, kept upstairs, who might be embarrassingly coming downstairs, incontinently, and cause trouble.

Episode one: "Shadows of Doubt"

While the early deists were busy reconstructing Christianity, at the same time being very careful to avoid the accusation of atheism, the world of science had been steadily progressing.

Episode two: "Noughts and Crosses"

Ever since the Reformation, there's a sense in which the road to atheism was paved not with science, but with religious intentions.

Episode two: "Noughts and Crosses"

Although he never admitted himself to be an atheist as such, he was clearly and unarguably the most vividly elegant and eloquent skeptic of them all. I'm referring, of course, to the great Scottish philosopher David Hume.

Episode two: "Noughts and Crosses"

There were academics and theologians who spent hours calculating what they thought was the precise age of the Earth, on the basis of the Biblical account of it. And as early as 1650, James Ussher had come to the startlingly precise conclusion that the Earth was created in 4004 B.C. on October the 22nd – in the evening, apparently. What God had been doing that morning is still open to conjecture.

Episode three: "The Final Hour"

There is one aspect of our own mentality for which it's difficult as yet to foresee what type of explanation would even be relevant. I'm referring, of course, to consciousness. The point is that although I have no reason to believe that my consciousness is implemented by anything other than my brain, I remain convinced that there's something impenetrably mysterious about the relationship between brains and thoughts. And you can understand, therefore, why it's so hard to imagine, let alone tolerate, the idea that the death of the brain necessarily leads to the end of the personal self – and this, of course, is the "trump card" with which religion has consistently played.